Donald Trump Jr has been forced to release damning emails that show he welcomed what he was told was a Russian government attempt to harm Hillary Clinton’s election campaign.

The emails show music promoter Rob Goldstone telling the future US president’s son that “the crown prosecutor of Russia” had offered “to provide the Trump campaign with some official documents and information that would incriminate Hillary and her dealings with Russia and would be very useful to your father”.

Goldstone adds: “This is obviously very high level and sensitive information but is part of Russia and its government’s support for Mr Trump.”

Trump Jr replies 17 minutes later and welcomes the offer. “If it’s what you say, I love it, especially later in the summer.”

In a later email, Goldstone describes the Russian lawyer they were due to meet, Natalia Veselnitskaya, as a “Russian government attorney”.

The formatting of the emails suggests that Trump Jr forwarded the whole chain to Paul Manafort, then Trump’s campaign chairman, and Jared Kushner, Trump Jr’s brother-in-law, before the meeting the three attended with Veselnitskaya.

Trump Jr released the email exchange on Tuesday apparently to pre-empt their publication by the New York Times, which, this weekend, first broke the news of his meeting with Veselnitskaya in June last year. Veselnitskaya had promised compromising information about Clinton but apparently failed to deliver.

The president’s eldest son denies any wrongdoing and tweeted on Tuesday: “Media and Dems are extremely invested in the Russia story. If this nonsense meeting is all they have after a year, I understand the desperation!”

On Monday night, the Times had reported that Trump Jr was informed in an email before a meeting with the lawyer that damaging information about Clinton to be handed over was part of an effort by the Russian government to help the Trump campaign.

The Times did not publish the Goldstone email, but reported that three different people had described it to them. On Tuesday the paper published the email, and Trump Jr posted the email chain to Twitter.